<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>后盾人</title>
  </head>
  <body></body>
  <script>
    function A() {}
    function B() {}
    function C() {}
    let c = new C();
    B.prototype = c;
    let b = new B();
    A.prototype = b;
    let a = new A();
    //A.prototype
    console.log(a instanceof A);
    console.log(a instanceof C);
    console.log(a instanceof C);
    console.log(b instanceof A);
  </script>
</html>
